Spy chief finds MI5 blunder by Home Secretary

Home Secretary Theresa May signed an MI5 warrant containing information on the wrong person, the Intelligence Services Commissioner revealed today.

Sir Mark Waller told how he found the “unacceptable” blunder, though it did not make the warrant unlawful.

The error is believed to be due to the Home Office failing to change properly a warrants template previously used for another case. Sir Mark questioned the Home Secretary on the case, which he unearthed during inspections.

In his report for 2012, he wrote: “Unfortunately, I must report that this year I did discover an error. I stress that no unlawful activity occurred but I still viewed this as extremely serious as it was missed by so many people.” He did not say if the warrant was for surveillance or to enter a property.

He also revealed the number of re- ported or discovered errors rose to 30 last year from 24 in 2011.